I just noticed this new knife that Keichi of BluewayJapan has listed. It is a Yusuke solid white steel single bevel mukimono. It does seem to have a concave back, so it should be a true single bevel knife. Although it is a solid steel, but there is no claim that it is a honyaki. Listing seems to claim similar HRC, 60-61, to their gyuto range though.